Module: GraphQL::Schema::Member::HasDataloader

Included in:
Interface::DefinitionMethods, Object, Resolver
Defined in:
lib/graphql/schema/member/has_dataloader.rb

Overview

Shared methods for working with Dataloader inside GraphQL runtime objects.

Instance Method Summary collapse

Instance Method Details

#dataload(source_class, *source_args, load_key) ⇒ Object

A shortcut method for loading a key from a source. Identical to dataloader.with(source_class, *source_args).load(load_key)

Parameters:

  • source_class (Class<GraphQL::Dataloader::Source>)
  • source_args (Array<Object>) —

    Any extra parameters defined in source_class's initialize method

  • load_key (Object) —

    The key to look up using def fetch


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# File 'lib/graphql/schema/member/has_dataloader.rb', line 19

def dataload(source_class, *source_args, load_key)
  dataloader.with(source_class, *source_args).load(load_key)
end

#dataload_association(record = object, association_name, scope: nil) ⇒ ActiveRecord::Base?

Look up an associated record using a Rails association (via Dataloader::ActiveRecordAssociationSource)

Examples:

Looking up a belongs_to on the current object

dataload_association(:parent) # Equivalent to `object.parent`, but dataloaded

Looking up an associated record on some other object

dataload_association(comment, :post) # Equivalent to `comment.post`, but dataloaded

Parameters:

  • association_name (Symbol) —

    A belongs_to or has_one association. (If a has_many association is named here, it will be selected without pagination.)

  • record (ActiveRecord::Base) (defaults to: object) —

    The object that the association belongs to.

  • scope (ActiveRecord::Relation) (defaults to: nil) —

    A scope to look up the associated record in

Returns:

  • (ActiveRecord::Base, nil) —

    The associated record, if there is one


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# File 'lib/graphql/schema/member/has_dataloader.rb', line 51

def dataload_association(record = object, association_name, scope: nil)
  source = if scope
    dataloader.with(Dataloader::ActiveRecordAssociationSource, association_name, scope)
  else
    dataloader.with(Dataloader::ActiveRecordAssociationSource, association_name)
  end
  source.load(record)
end

#dataload_record(model, find_by_value, find_by: nil) ⇒ ActiveRecord::Base?

Find an object with ActiveRecord via Dataloader::ActiveRecordSource.

Examples:

Finding a record by ID

dataload_record(Post, 5) # Like `Post.find(5)`, but dataloaded

Finding a record by another attribute

dataload_record(User, "matz", find_by: :handle) # Like `User.find_by(handle: "matz")`, but dataloaded

Parameters:

  • model (Class<ActiveRecord::Base>)
  • find_by_value (Object) —

    Usually an id, might be another value if find_by: is also provided

  • find_by (Symbol, String) (defaults to: nil) —

    A column name to look the record up by. (Defaults to the model's primary key.)

Returns:

  • (ActiveRecord::Base, nil) 

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# File 'lib/graphql/schema/member/has_dataloader.rb', line 32

def dataload_record(model, find_by_value, find_by: nil)
  source = if find_by
    dataloader.with(Dataloader::ActiveRecordSource, model, find_by: find_by)
  else
    dataloader.with(Dataloader::ActiveRecordSource, model)
  end

  source.load(find_by_value)
end

#dataloader ⇒ GraphQL::Dataloader

Returns The dataloader for the currently-running query.

Returns:


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# File 'lib/graphql/schema/member/has_dataloader.rb', line 10

def dataloader
  context.dataloader
end